WASHINGTON — As Oklahoma’s attorney general, Scott Pruitt, now the Environmental Protection Agency administrator, closely coordinated with major oil and gas producers, electric utilities and political groups with ties to the libertarian billionaire brothers Charles G. and David H. Koch to roll back environmental regulations, according to over 6,000 pages of emails made public on Wednesday.

The publication of the correspondence comes just days after Mr. Pruitt was sworn in to run the E.P.A., which is charged with reining in pollution and regulating public health. Senate Democrats tried last week to postpone a final vote until the emails could be made public, but Republicans beat back the delay and approved his confirmation on Friday largely along party lines.

The impolitic tone of many of the emails cast light on why Republicans were so eager to beat the release. And although the contents of the emails were broadly revealed in The New York Times in 2014, the totality of the correspondences captures just how much at war Mr. Pruitt was with the E.P.A. and how cozy he was with the industries that he is now charged with policing.

“Thank you to your respective bosses and all they are doing to push back against President Obama’s E.P.A. and its axis with liberal environmental groups to increase energy costs for Oklahomans and American families across the states,” said one email sent to the offices of Mr. Pruitt and an Oklahoma congressman in August 2013 by Matt Ball, an executive at Americans for Prosperity. That nonprofit group is funded in part by the Kochs, the Kansas-born business executives who spent much of the past decade combating federal regulations, particularly in the energy sector. “You both work for true champions of freedom and liberty!” the note said.

Environmental groups rushed to condemn the correspondence.

“This extensive trail of emails reads like a yearslong chain of love letters between soul mates,” said Ken Cook, the president of the Environmental Working Group.

Mr. Pruitt has been among the most contentious of President Trump’s cabinet nominees. Environmental groups, Democrats in Congress and even current E.P.A. employees have protested his ties to energy companies, his efforts to block and weaken major environmental rules, and his skepticism of the central mission of the agency he now leads. As soon as this week, Mr. Trump is expected to announce at least two executive orders directing Mr. Pruitt to begin rolling back and weakening a set of Obama-era E.P.A. regulations aimed at limiting emissions that cause global warming, and at pollution in the nation’s rivers, streams and wetlands.

An Oklahoma judge ordered the release of the emails in response to a lawsuit by the Center for Media and Democracy, a liberal watchdog group. Many of the emails are copies of documents previously provided to The Times, which examined Mr. Pruitt’s interaction with energy industry players his office helps regulate.

The companies provided him with draft letters to send to federal regulators in an attempt to block regulations on greenhouse gas emissions from oil and gas wells, ozone air pollution and chemicals used in hydraulic fracturing, or fracking, the technique of injecting chemicals underground to extract oil and gas, the emails show.

Industry executives and Mr. Pruitt held secret meetings to discuss more comprehensive ways to combat the Obama administration’s environmental agenda, and companies and the organizations they funded repeatedly praised Mr. Pruitt and his staff for the assistance in their campaign.

The emails show that his office corresponded with those companies — including Devon Energy, an Oklahoma oil and gas producer, and American Electric Power, an Ohio-based utility — in efforts to weaken federal environmental regulations, the same rules he will now oversee.

“Please find attached a short white paper with some talking points that you might find useful to cut and paste when encouraging states to file comments on the S.S.M. rule,” wrote Roderick Hastie, a lobbyist at Hunton & Williams, a law firm that represents major utilities, including Southern Company, urging Mr. Pruitt’s office to file comments on a proposed E.P.A. rule related to so-called start-up, shutdown and malfunction emissions.

The most frequent correspondence was with Devon Energy, which has aggressively challenged rules proposed by the E.P.A. and the Department of Interior’s Bureau of Land Management, which controls drilling on federal lands. In the 2014 election cycle, Devon was one of the top contributors to the Republican Attorneys General Association, which Mr. Pruitt led for two years during that period.

In a March 2013 letter to Mr. Pruitt’s office, William Whitsitt, then an executive vice president of Devon, referred to a letter his company had drafted for Mr. Pruitt to deliver, on state stationery, to Obama administration officials. Mr. Pruitt, meeting with White House officials, made the case that the rule to rein in methane emissions would harm his state’s economy. His argument was taken directly from Mr. Whitsitt’s draft language.

“To follow up on my conversations with Attorney General Pruitt and you, I believe that a meeting — or perhaps more efficient, a conference call — with O.I.R.A. (the O.M.B. Office of Information and Regulatory Analysis) on the B.L.M. rule should be requested right away,” Mr. Whitsitt wrote to a senior member of Mr. Pruitt’s staff, referring to the section of the White House Office of Management and Budget that coordinates regulations throughout the government. “The attached draft letter (or something like it that Scott is comfortable talking from and sending to the acting director to whom the letter is addressed) could be the basis for the meeting or call.”

In an email from January of that year, Mr. Whitsitt thanked Mr. Pruitt’s office for pushing the Bureau of Land Management to loosen a proposed regulation on fracking.

“I just let General Pruitt know that B.L.M. is going to propose a different version of its federal lands hydraulic fracturing rule thanks to input received — thanks for the help on this!” Mr. Whitsitt wrote.

“This argument is more credible coming from a state,” Richard Moskowitz, general counsel at the American Fuel & Petrochemical Manufacturers, wrote to one of Mr. Pruitt’s aides.

Later that year, Mr. Pruitt filed petitions against both those rules.

On Tuesday afternoon, Mr. Pruitt addressed career E.P.A. employees to assuage unease with — and even rebellion against — their new boss. Mr. Pruitt praised the employees for their years of public service and promised to listen to them.

“I believe that we as an agency, and we as a nation, can be both pro-energy and jobs and pro-environment. But we don’t have to choose between the two,” he told employees, even as he stressed that federal authority should be diminished, and that regulatory powers and oversight of pollution should be left largely to the states.

“Federalism matters,” he said.

The E.P.A. and the White House did not respond to requests for comment on the emails.

The emails do not appear to include any request for his intervention explicitly in exchange for campaign contributions, although Mr. Pruitt was separately working as a member of the Republican Attorneys General Association to raise money from many of the same companies.

The Oklahoma attorney general’s office withheld some documents, asking the judge to determine if they can be exempted from the order requiring their release. Other open-records requests from the Center for Media and Democracy, The Times and other news organizations remain pending.

Correction:Feb. 22, 2017

An earlier version of this article misstated the role of Roderick Hastie, an employee at the law firm Hunton & Williams. He is a lobbyist, not a lawyer.

A version of this article appears in print on , on Page A13 of the New York edition with the headline: E.P.A. Chief Was Cozy With Energy Industry, Trove of Emails Shows. Order Reprints | Today’s Paper | Subscribe